This invention relates to a semi-submersible vessel.
Many designs of semi-submersible floating platforms used for drilling or other offshore operations are based on the use of three or more vertical buoyant columns to support a deck at a safe distance above sea level, their bottom ends being attached to underwater chambers forming pontoons to provide additional buoyancy.
The operating deck is designed for carrying equipment and living quarters and may contribute to the rigidity of structure. The deck then forms a strong box structure enclosing a number of tween decks and integrated with the tops of the columns. Columns and bracings between columns are subject to wave and current forces and their points of attachment are susceptible to material fatigue.